Solving the Vehicle Routing Problem with Multiple Trips and Simultaneous Delivery-Pickup for Drinking Water Distribution Company

Abstract

Transportation is a crucial factor in distribution, as it can save up to 50% of the overall costs. The Vehicle Routing Problem with Multiple Trips and Simultaneous Delivery-Pickup (VRPMTSDP) has become one of the most important areas of logistic management. This problem is an extension of the Vehicle Routing Problem (VRP), including the following characteristics: multiple trips and simultaneous delivery-pickup. A set of homogenous vehicles is available at the depot to deliver and pick up customer’s goods. The route of each vehicle in serving customers can cover more than one trip. This research helps to solve the problems faced by the Drinking Water Distribution Company in Bandung. Currently, they face high delivery costs and frequent driver overtime when returning to the depot, resulting in high overtime expenses. This problem can be classified as VRPMTSDP, with the aim of minimizing delivery costs. We propose a Tabu Search with the initial solution obtained using Saving Matrix and Nearest Neighbor. The results show that the proposed route by the Tabu Search algorithm saves delivery costs of 11.22% rather than the company’s current route. Sensitivity analyses are presented to understand the impact of various Tabu Search operators on the delivery cost of VRPMTSDP.